I played some online battles after a year but every match was really laggy. The last battle was unplayable because of the lagg. I tired to switch off the virus protection and the firewall but no success. (and of course the other program that uses the internet was turned off) My connection is good 25 / 2,5 mbit. What do you think what is the problem?

Hmm, I am not so good in game's technical support, but I could try say something about it.

There could be few problems.

1. Who hosted and played online battles? You should remember that the poorest computer and internet can slow down game play. If someone who play with you had worse parameters this can inflict some problems to you too.

Then you could try avoid battles hosted and played with much poorer computers than these recomended.

2. How many units were used in tha game?

Every game have some units limits. C2 allow play with 2.500-3.000 men population per one player without lagg. Bigger population or too many units and too many formations which operate all together at once can inflict laggs. Too many moved units at once made some troubles. When they operate all together they are hard control able too.

Then you could try play faster from the begining of the game and try attack immediately as you can use formations. It little bit silly case, but it works. You can kill some men faster and there still will less amount of population in the game. But when you want to play big battles with large armies then this tactic could be problematic. Nevertheless you still could try make some actions for each formation separately and play it simultanously, but do not use all formations at once.

3. How many earlier game plays were recorded on your computer?

If you play and record a lot of games it needs some memory. The game could slow down when there were too many recorded game plays.

You can find proper game folder on your computer and can delete (erase) some old or usless skirmish or battles.rec files.